In their pending lawsuit, the Yelpers compare Yelp to a “slave ship.” Suing for wages, authors of online reviews for the crowdsourced site argue that Yelp could not be sustained or make profits without their work. That’s true on some level, of course. It’s also widely understood that Yelp reviews are written without pay for the good of the service, which helps millions of users avoid terrible kebabs and find hairdressers who totally get their curls.

Four plaintiffs filed the class-action suit in a California U.S. district court last week. This week, Yelp provided Fast Company with a response:

This is a textbook example of a frivolous lawsuit, it is unfortunate the court has to waste its time adjudicating it and we will seek to have it dismissed. The argument that voluntarily using a free service equates to an employment relationship is completely without merit, unsupported by law and contradicted by the dozens of websites like Yelp that consumers use to help one another.

Tech pundits have called the suit “ridiculous” and “incredibly stupid.” It’s also the latest in a long string of problems surrounding online reviews.

There is a legitimate fear that whatever review you’re reading might be fake. The New York Attorney General recently settled a case with 19 businesses who agreed to pay a total of $350,000 after being accused of selling or forging reviews. Yelp itself is constantly using software to weed through millions of phony and legitimate reviews submitted to their site. According to a recent blog post from the company, about 75% make it through their filter to the general public. And a disheartening Gartner study estimates that up to 15% of all online reviews will be fake by next year.

Then there’s the swag issue. The Federal Trade Commission has been targeting household-name retailers like Ann Taylor LOFT for giving free stuff to bloggers who attend events like store openings or collection previews. And top reviewers on Amazon, part of an invitation-only program called Amazon Vine, are regularly getting free products to pen their opinions, NPR reports. They can’t resell or gift the merchandise, and an Amazon rep points out that Vine reviewers are more stingy with their stars than users across the site. But the basic problem remains: compensation in things or dollars can lead to bias, which can lead to misleading endorsements.

In their terms of service, Yelp asks all users not to violate the site’s content guidelines by “compensating someone or being compensated” to write a review. Perhaps they need to write it out in bold that compensation won’t be coming from their end, either.